Serotonin uptake and release by platelets adhering to polyethylene.

Heparinized human blood containing platelets labelled with 14C-serotonin and 51Cr was exposed to a polyethylene surface by rotation in Chandler loops. Both uptake of platelets on the surface and platelet aggregation in the blood occurred. More 14C- than 51Cr activity accumulated on the surface. It was demonstrated that this was due to an active uptake of 14C-serotonin by the surface-adherent platelets, which also retained their capacity to exert a release reaction.